Did the 12K service myself last night and...

[DownrangeFuture]

While I was at it, I changed the spark plugs. Due at 8,000 miles. Oops. Anyway, as I was putting the bike back together I gave her a test fire. I thought to myself, "Man I love that throaty twin sound, its just so... " So I pulled it apart and noticed one of the leads to the coils was off. No biggie, so I put it back on. Fired her up again and she was running rough as heck, popping and missing, etc. So I tore her down again, gave each of the plugs a quarter turn and seated the plug wires firmly again.

Now when I turn it on, it smells like it's running rich, the idle was way low at around 800rpm (which I adjusted), and until it's hot it sounds like it's missing every now and then and it bogs under anything more than a quarter throttle. That's the only part of the ignition system I messed with so it's bound to be in there somewhere. All of the old plugs looked worn, but with nice even tan coats on all of them.

The only thing I can think to do is to pull the plugs and check them and the gaps again. Ideas? I didn't touch the throttle body at all. Just the idler. I didn't change the air filter because it didn't look that bad. But I suppose I could, but it was running like a dream before the plug swap so, I wouldn't think that's the issue. The rest of the service was mostly just repacking bearings and greasing the levers.

 

[FB400]

definately sounds like the gap clearances are off. I had to adjust the gaps on mine coming right out of the packages (didn't come gapped correctly). I am sure you are making sure the plug wires are in the correct order already. btw, I used the stock NGK plugs

 

[DownrangeFuture]

Yeah, I used the stock ones too. NGK didn't list any alternatives, so I just went stock. And I'm fairly certian I went 1 to 4 left to right, but the second time I KNOW I checked each plug wire.

 

[FinalImpact]

OK - picture this. . .

IT seems we have enough posts on coil & coil-wire related issues to make a point that these assemblies are subject to failure.

When you're coils didn't have a proper destination for all that energy to be delivered too (the spark plugs gap), it likely jumped somewhere else. Those few moments in time before you shut it down could have damaged the fragile coils. Its why IT IS REQUIRED to ground the output of coil(s) during compression tests and things of that nature so that energy has a path and doesn't jump back to the input wires feeding it (ECU/ECM etc) or through the body of the coils to ground.

I think what people fail to see is the "coil resistance test" only tests the coil windings for shorts and opens. But in the real world we also need to know if the dialectic insulating ability of the coil and wires are intact. If its not intact, the energy leaks through the coils body and is not delivered to the spark plug and this creates a misfire. Anyway it takes an expensive piece of equipment to test a coil for break-down and most of us have no means of performing this test. So just because a set of coils and wires pass the electrical resistance test, it doesn't mean they will work as expected.

But please don't jump to conclusions. Try putting the old plugs back in and check the caps and wires for a good secure connection as Spark plugs saturated in gas can short and cause the problem you mention.

 

[DownrangeFuture]

Nah, it was the incoming leads. The coil wasn't getting any power at all. So the coils are fine. As an electronics technician, I know the implications of running a transformer with a shoddy connection on one side. The coils don't like being a capacitor. As a 2M (micro-miniature repair i.e. soldering on things so small you need a microscope) tech, I tell people all the time you can't really test a transformer without a load.

Anyway, I pulled all the plugs and checked the gaps. I totally didn't even look last night apparently. the plug for #4 had a gap of less than the 0.2mm my tester goes down to. Set that gap and left that hole open while I checked the other three (which were all fine) and played with my new torque wrench. My elbow is way off, mostly to the tight side. But everything is torqued right now.

So when I put the bike back together, after a few complaints it seems to run fine now. Just the half second bog when you get on the throttle hard from closed that it's always done. A smooth but quick roll on has no bog.

Just need to get out for a test ride here soon. I swear, my pills make me brain dead sometimes.

 

[DownrangeFuture]

Fixed it, it seems like. Figured out that the clicking I've been hearing is my chain. I don't think the PO ever greased the chain. I've got a link sitting on my back sprocket, still bent ****eyed. And it's not quite 12,000 yet. 11,515 or so.

Thanks for the input guys. I can see why doc told me I can't work on aircraft with these meds. I think I just need to start making lists when I work on stuff and follow them.

 

[dean owens]

...I gave her a test fire. I thought to myself, "Man I love that throaty twin sound, its just so... "

:rof: :rof: :rof: